A twin-screw extruder for diaphragm production

Abstract

The present invention relates to the technical field of screw extruders, and specifically to a twin-screw extruder for diaphragm production, comprising an extrusion component, including an extrusion barrel, wherein two rotating shafts are rotatably installed in the extrusion barrel, and the circumferential side of the rotating shaft is fixedly connected with a threaded member and a kneading block; a feeding component, including a feeding barrel, the bottom end of which is connected to the extrusion barrel; an external temperature control component, including a plurality of heating modules, for heating the extrusion barrel; an internal heating component, for heating the rotating shaft; a preheating component; and a temperature sensing component. The twin-screw extruder for diaphragm production can directly heat the rotating shaft of the extrusion component by utilizing the temperature heated by the extrusion barrel through the cooperation of the external temperature control component and the internal heating component, thereby increasing the heating speed of the rotating shaft and reducing heat energy loss and waste of production time. At the same time, the temperature difference between the extrusion barrel and the rotating shaft can be reduced by synchronously heating the extrusion barrel and the rotating shaft, thereby increasing the heating uniformity of the raw materials and thus improving the extrusion quality.

Description

Technical Field

[0001] The invention relates to the technical field of screw extruders, in particular to a twin-screw extruder for producing diaphragms. Background Art

[0002] Lithium battery separator is the inner component of lithium battery. In the structure of lithium battery, separator is one of the key inner components. The performance of separator determines the interface structure and internal resistance of battery, which directly affects the capacity, cycle and safety performance of battery. The production of battery separator requires that the raw materials are proportioned, transported to the extrusion device for melting and plasticization, and then formed into base film by casting, and then formed by stretching and other processes. Twin-screw extruder is often used in this process.

[0003] Battery separators have extremely high requirements for thickness uniformity, mechanical properties, air permeability, physical and chemical properties, etc. In order to ensure the plasticization quality and product performance of battery separators, the twin-screw extruder needs to be preheated before formal operation so that the extrusion barrel reaches a certain temperature to avoid affecting the separator extrusion quality due to temperature fluctuations.

[0004] However, the current twin-screw extruder is limited by the structure, and the heating component is set outside the extrusion shell. During preheating, the shell heats up quickly, and the extrusion screw inside the shell cannot directly contact the heating component. The heating speed is slow, and it usually takes several hours to reach the required temperature, resulting in a waste of heat energy and production time. In addition, since the temperature radiates from the outside of the shell to the inside, it will cause a large temperature difference between the shell and the extrusion screw, making the plasticization degree of the material uneven, affecting the extrusion quality. Summary of the invention

[0005] The purpose of an embodiment of the present invention is to provide a twin-screw extruder for diaphragm production, which solves the problem that when the current twin-screw extruder for diaphragm production is heated, the heating rate of the extrusion screw is significantly slower than the heating rate of the outer shell, and the temperature difference between the extrusion screw and the outer shell is large.

[0006] To achieve the above object, the present invention provides the following technical solutions:

[0007] A twin-screw extruder for producing a diaphragm comprises an extrusion component, including an extrusion barrel, wherein two rotating shafts are rotatably mounted in the extrusion barrel, and a threaded member and a kneading block are fixedly connected to the circumference of the rotating shaft;

[0008] A feeding component, comprising a feeding cylinder, the bottom end of which is connected to the extrusion cylinder;

[0009] An external temperature control component, including a plurality of heating modules, for heating the extrusion barrel;

[0010] An internal heating component, used for heating the rotating shaft;

[0011] A preheating component, used for heating the feed barrel;

[0012] The temperature sensing component is used to control the heating temperature of the feed barrel by the preheating component.

[0013] As a preferred technical solution, the internal heating component includes a flow guide tube, one end of which is connected to two flow shunt tubes, and one end of the two flow shunt tubes away from the flow guide tube is respectively connected to a heat flow inlet tube;

[0014] The centers of the two rotating shafts are provided with fluid channels along the axial direction, and the two fluid channels are respectively connected with two heat flow inlet pipes.

[0015] As a preferred technical solution, the internal heating component also includes a heat-conducting shell, which is mounted on one of the heating modules. The interior of the heat-conducting shell is hollow and filled with liquid. The top of the heat-conducting shell is connected to an end of the guide tube away from the diversion tube, so as to guide the steam generated after the liquid boils.

[0016] As a preferred technical solution, a plurality of expansion channels are provided in the rotating shaft, the inner side of the expansion channels is communicated with the fluid channel, and the outer side extends radially outward along the rotating shaft, and the expansion channels are located inside the kneading block.

[0017] As a preferred technical solution, the preheating component includes a heating sleeve, which is sleeved on the circumference of the feed barrel. The heating sleeve is hollow inside and is connected to a pump body through a pipeline, and the input end of the pump body is connected to a connecting pipe.

[0018] As a preferred technical solution, the end of the connecting pipe away from the heating sleeve is connected to two collecting pipes, the ends of the two collecting pipes away from the connecting pipe are respectively connected to heat outflow pipes, and the two heat outflow pipes are respectively connected to the ends of the two fluid channels away from the heat inlet pipe.

[0019] As a preferred technical solution, the interior of the heating sleeve is connected to a first return pipe, and one end of the first return pipe away from the heating sleeve is connected to the interior of the heat-conducting shell.

[0020] As a preferred technical solution, the temperature sensing component includes a diverter shell, in which an inlet pipe and an outlet pipe are respectively connected, and a piston in the diverter shell is connected to a sealing rod.

[0021] As a preferred technical solution, a second return pipe is connected inside the diverter shell, and one end of the second return pipe away from the diverter shell is connected to the inside of the heat-conducting shell.

[0022] As a preferred technical solution, the temperature sensing component further includes a memory spring, one end of which is fixedly connected to the inner wall of the diverter shell, and the other end of which is fixedly connected to one end of the sealing rod.

[0023] By means of the above technical solution, the present invention provides a twin-screw extruder for producing diaphragms, which has at least the following beneficial effects:

[0024] (1) The twin-screw extruder for diaphragm production can directly heat the shaft of the extrusion component by using the temperature of the extrusion barrel through the cooperation of the external temperature control component and the internal heating component, thereby increasing the heating speed of the shaft and reducing heat energy loss and waste of production time. At the same time, the temperature difference between the extrusion barrel and the shaft can be reduced by synchronous heating, thereby improving the heating uniformity of the raw materials and thus improving the extrusion quality.

[0025] (2) The twin-screw extruder for diaphragm production is provided with a preheating component, which can utilize the residual heat after the extrusion component is heated to heat the feed barrel, thereby preheating the raw materials, reducing the temperature difference of the raw materials after entering the high-temperature extrusion barrel, and improving the plasticization efficiency of the raw materials.

[0026] (3) The twin-screw extruder used in the production of the diaphragm is equipped with a temperature sensing component, which can use the temperature sensing element to control whether the heat flow enters the heating sleeve, thereby avoiding the feed barrel temperature being too high and preventing the material from overheating and affecting its plasticization quality. BRIEF DESCRIPTION OF THE DRAWINGS

[0027] The accompanying drawings described herein are used to provide a further understanding of the present invention and constitute a part of this application:

[0028] Figure 1 It is a schematic diagram of the overall structure of an embodiment of the present invention;

[0029] Figure 2 A cross-sectional view of an extrusion barrel in an embodiment of the present invention;

[0030] Figure 3 is a schematic diagram of an extrusion component in an embodiment of the present invention;

[0031] Figure 4 is a schematic diagram of an internal heating component in an embodiment of the present invention;

[0032] Figure 5 Schematic diagram of a fluid channel and a flow expansion channel in an embodiment of the present invention;

[0033] Figure 6 is a schematic diagram of a temperature sensing component in an embodiment of the present invention;

[0034] Figure 7 4 is a cross-sectional view of a splitter shell in an embodiment of the present invention.

[0035] In the figure: 1. extrusion component; 101. extrusion barrel; 102. rotating shaft; 1021. fluid channel; 1022. expansion channel; 103. screw member; 104. kneading block; 105. motor; 2. feeding component; 201. hopper; 202. screw conveyor; 203. feeding barrel; 3. external temperature control component; 301. heating module; 4. internal heating component; 401. heat-conducting shell; 402. flow guide tube; 40 3. shunt pipe; 404. heat flow inlet pipe; 5. preheating component; 501. heating sleeve; 502. pump body; 503. connecting pipe; 504. collecting pipe; 505. heat flow outlet pipe; 506. first return pipe; 6. temperature sensing component; 601. shunt shell; 6011. extension groove; 602. outlet pipe; 603. inlet pipe; 604. memory spring; 605. sealing rod; 606. second return pipe. DETAILED DESCRIPTION

[0036] The following will be combined with the drawings in the embodiments of the present invention to clearly and completely describe the technical solutions in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0037] Embodiment 1

[0038] See also Figure 1-Figure 5 This embodiment provides a twin-screw extruder for diaphragm production, including an extrusion component 1, a feeding component 2 and an external temperature control component 3.

[0039] Among them, the extrusion component 1 includes an extrusion barrel 101, in which two extrusion screws are rotatably installed. The two extrusion screws have the same structure and both include a rotating shaft 102. The circumferential side of the rotating shaft 102 is fixedly connected with a threaded member 103 and a kneading block 104. There are at least three threaded members 103, and the pitch of the threaded member 103 gradually decreases along the extrusion direction. At least two groups of kneading blocks 104 are arranged and distributed between the threaded members 103, so as to improve the shearing and mixing ability of the device on the material.

[0040] The extrusion component 1 further includes a motor 105 , which is drivingly connected to the two rotating shafts 102 to provide torque for the rotation of the two rotating shafts 102 .

[0041] In this embodiment, the feeding component 2 includes a hopper 201, the bottom end of the hopper 201 is connected to a screw conveyor 202, one end of the screw conveyor 202 is connected to a feeding barrel 203, and the bottom end of the feeding barrel 203 is connected to the extrusion barrel 101 for conveying materials between the two extrusion screws.

[0042] In this embodiment, the external temperature control component 3 includes a plurality of heating modules 301 , and the plurality of heating modules 301 are distributed along the length direction of the extrusion screw for performing zoned heating on the extrusion barrel 101 .

[0043] Before the twin-screw extruder device works, the extrusion component 1 needs to be heated in advance. During heating, the heating module 301 can be in direct contact with the extrusion barrel 101, so that the surface temperature of the extrusion barrel 101 changes faster, while there is a certain distance between the rotating shafts 102, and the temperature changes slower. The traditional rotating shaft 102 is made of solid metal, and the heating rate is slow when it is not in direct contact with the heating module 301, resulting in a temperature difference inside the extrusion barrel 101, affecting the uniformity of the thermal change of the material. Generally speaking, in order to overcome the uneven temperature inside the extrusion component 1, so that the rotating shaft 102 and the threaded member 103 and the kneading block 104 on the rotating shaft 102 are heated to a suitable temperature, it is necessary to increase the heating time, increase energy consumption and investment.

[0044] To this end, the twin-screw extruder for diaphragm production further includes an internal heating component 4 , which is used to directly heat the rotating shaft 102 , increase the heating rate of the rotating shaft 102 , and reduce the temperature difference between the rotating shaft 102 and the extrusion barrel 101 .

[0045] In this embodiment, the internal heating component 4 includes a heat-conducting shell 401, which is sleeved on one of the heating modules 301. The heat-conducting shell 401 is in the shape of a "U". The interior of the heat-conducting shell 401 is hollow and filled with liquid, which is preferably water. When the heating module 301 is working, the heat-conducting shell 401 will heat up accordingly, causing the liquid inside it to boil and generate steam, and the rotating shaft 102 is heated by the flowing steam. Specifically, the top of the heat-conducting shell 401 is fixed and connected to a guide tube 402, which is used to guide the steam generated after the liquid boils. The end of the guide tube 402 away from the heat-conducting shell 401 is connected to two shunt tubes 403, and the ends of the two shunt tubes 403 away from the guide tube 402 are respectively connected to heat flow inlet pipes 404. The hot steam enters the two heat flow inlet pipes 404 after being shunted by the two shunt tubes 403, and then is respectively introduced into the two extrusion screws, thereby heating the two extrusion screws from the inside at the same time. Specifically, the centers of the two rotating shafts 102 are provided with fluid channels 1021 along the axial direction, and the two fluid channels 1021 are respectively connected to the two heat flow inlet pipes 404, so that hot steam enters the interior of the rotating shaft 102, and the heat directly contacts the extrusion screw, thereby increasing the heating speed of the extrusion screw. In addition, the rotating shaft 102 is rotatably mounted on the heat flow inlet pipe 404, which does not affect the normal operation of the extrusion screw, and a sealing structure is used between the two to seal to prevent steam from overflowing.

[0046] See also Figure 5A plurality of expansion channels 1022 are provided in the rotating shaft 102. The expansion channels 1022 are annular. The inner peripheral side of the annular expansion channel 1022 is connected to the fluid channel 1021, and the outer peripheral side extends radially outward along the rotating shaft 102. The expansion channels 1022 are located on the inner side of the kneading block 104. By providing the expansion channels 1022, the distance between the hot steam and the kneading block 104 can be shortened, so that the kneading block 104 can be in contact with the heat more quickly, thereby increasing the temperature of the kneading block 104, ensuring the fluidity of the material when passing through the kneading block 104, and improving the mixing effect.

[0047] Embodiment 2

[0048] See also Figure 1-Figure 7 On the basis of Example 1, a twin-screw extruder for diaphragm production provided in this embodiment further includes a preheating component 5, which is used to heat the feed barrel 203, thereby reducing the temperature difference when the material enters the extrusion barrel 101 and accelerating the plasticization process of the material.

[0049] Specifically, the preheating component 5 in this embodiment includes a heating sleeve 501, which is annular and is sleeved on the side of the feed barrel 203. The interior of the heating sleeve 501 is hollow, so that the heat flow can enter the interior of the heating sleeve 501, thereby heating the feed barrel 203. The bottom position of the heating sleeve 501 is connected to the pump body 502 through a temperature sensing component 6. The temperature sensing component 6 is used to control the temperature of the heat flow entering the heating sleeve 501 to avoid the temperature of the heating sleeve 501 being too high, thereby affecting the plasticization quality of the material.

[0050] Furthermore, the input end of the pump body 502 is connected with a connecting pipe 503 for sucking the heat flow so that the heat flow enters the heating sleeve 501. The end of the connecting pipe 503 away from the heating sleeve 501 is connected with two collecting pipes 504, and the ends of the two collecting pipes 504 away from the connecting pipe 503 are respectively connected with heat outflow pipes 505, and the two heat outflow pipes 505 are respectively connected with the ends of the two fluid channels 1021 away from the heat flow inlet pipe 404, and the heat flow inlet pipe 404 is rotatably connected with the rotating shaft 102. After the hot steam flows out from the inside of the rotating shaft 102, it will be collected into the connecting pipe 503 through the heat outflow pipe 505 and the collecting pipe 504, and finally enter the heating sleeve 501 through the pump body 502 and the temperature sensing component 6, so as to further utilize the steam heat. A first return pipe 506 is fixed near the bottom of the heating sleeve 501 and connected thereto. One end of the first return pipe 506 away from the heating sleeve 501 is connected to the inside of the heat-conducting shell 401 to guide the cooled steam back into the heat-conducting shell 401 for reheating, thereby achieving a complete heat cycle.

[0051] Combination Figure 6 and Figure 7As shown, the temperature sensing component 6 includes a diverter shell 601, in which a cross groove is provided, and opposite ends of the cross groove are respectively connected with an inlet pipe 603 and an outlet pipe 602, wherein one end of the inlet pipe 603 away from the diverter shell 601 is connected to the pump body 502, and one end of the outlet pipe 602 away from the diverter shell 601 is connected to the heating sleeve 501, and the heat flow can enter the heating sleeve 501 through the pump body 502, the inlet pipe 603, the diverter shell 601 and the outlet pipe 602 in sequence.

[0052] As a preferred embodiment, the temperature sensing component 6 also includes a memory spring 604, which is a two-way memory spring made of shape memory alloy and has a temperature sensing drive function. The top of the memory spring 604 is fixedly connected to the inner wall of the cross groove, and the bottom is fixedly connected to the top of the sealing rod 605. The sealing rod 605 is connected to the piston of the inner wall of the cross groove. The sealing rod 605 is used to control the connection state between the inlet pipe 603 and the outlet pipe 602. When the temperature of the fluid entering the cross groove reaches the contraction threshold of the memory spring 604, the memory spring 604 will automatically contract and drive the sealing rod 605 to move upward, blocking the outlet pipe 602, so that the liquid flowing out of the inlet pipe 603 cannot enter the outlet pipe 602.

[0053] like Figure 7 As shown, the cross groove is connected with a second return pipe 606, and one end of the second return pipe 606 away from the diverter shell 601 is connected with the inside of the heat-conducting shell 401. The diverter shell 601 is also provided with an extension groove 6011, which is connected with both ends of the cross groove, and the liquid flowing out of the inlet pipe 603 can enter the extension groove 6011. When the memory spring 604 is extended, the sealing rod 605 will close the second return pipe 606, so that the liquid in the extension groove 6011 cannot enter the second return pipe 606. When the memory spring 604 is contracted, the sealing rod 605 moves upward to open the second return pipe 606, so that the liquid re-enters the heat-conducting shell 401 through the second return pipe 606.

[0054] Before using the twin-screw extruder for diaphragm production of the present invention, the extrusion barrel 101 is preheated by the heating module 301, and the heat generated by the preheating is directly transferred to the heat-conducting shell 401, so that the temperature of the heat-conducting shell 401 increases, and the liquid inside the heat-conducting shell 401 boils to generate steam. The steam rises and enters the two diverter pipes 403 through the guide pipe 402, and then enters the fluid channels 1021 in the two rotating shafts 102 through the two heat flow inlet pipes 404, respectively, to directly heat the rotating shafts 102. In this process, the steam in the fluid channel 1021 will diffuse into the multiple annular expansion channels 1022, so that the temperature of the kneading block 104 increases.

[0055] Subsequently, the steam will flow out through the other end of the rotating shaft 102 and enter the two hot outflow pipes 505, and then be collected into the connecting pipe 503 through the two collecting pipes 504, and then enter the inside of the diverter shell 601 through the pump body 502 and the inlet pipe 603, and contact the memory spring 604. In this process, the steam generates heat loss, the steam temperature decreases and condenses into liquid. When the temperature of the fluid entering the diverter shell 601 is lower than the contraction threshold of the memory spring 604, the memory spring 604 will remain in an extended state, at which time the outlet pipe 602 is in an open state, and the second return pipe 606 is in a closed state. The fluid will enter the heating sleeve 501 through the outlet pipe 602, so that the temperature of the heating sleeve 501 increases, and the material in the feed barrel 203 is preheated to accelerate the plasticization process of the material. The excess liquid in the heating sleeve 501 will return to the heat-conducting shell 401 through the first return pipe 506. When the temperature of the fluid entering the diverter shell 601 reaches the contraction threshold of the memory spring 604, the memory spring 604 will automatically contract and drive the sealing rod 605 to move upward, blocking the water outlet pipe 602 and opening the second return pipe 606, so that the overheated fluid can directly flow back into the heat-conducting shell 401 through the second return pipe 606, thereby avoiding the initial material temperature being too high, affecting its plasticization quality and extrusion process.

[0056] It should be noted that, in this article, relational terms such as first and second, etc. are only used to distinguish one entity or operation from another entity or operation, and do not necessarily require or imply any such actual relationship or order between these entities or operations. Moreover, the terms "include", "comprise" or any other variants thereof are intended to cover non-exclusive inclusion, so that a process, method, article or device including a series of elements includes not only those elements, but also other elements not explicitly listed, or also includes elements inherent to such process, method, article or device.

[0057] Although embodiments of the present invention have been shown and described, it will be appreciated by those skilled in the art that various changes, modifications, substitutions and variations may be made to the embodiments without departing from the principles and spirit of the present invention, and that the scope of the present invention is defined by the appended claims and their equivalents.

Claims

1. A twin-screw extruder for diaphragm production, characterized in that: include: An extrusion component (1) comprises an extrusion barrel (101), wherein two rotating shafts (102) are rotatably mounted in the extrusion barrel (101), and a threaded member (103) and a kneading block (104) are fixedly connected to the circumference of the rotating shaft (102); A feeding component (2) comprises a feeding cylinder (203), wherein the bottom end of the feeding cylinder (203) is connected to the extrusion cylinder (101); An external temperature control component (3) comprising a plurality of heating modules (301) for heating the extrusion barrel (101); An internal heating component (4) used for heating the rotating shaft (102); A preheating component (5) for heating the feed cylinder (203); The temperature sensing component (6) is used to control the heating temperature of the feed barrel (203) by the preheating component (5).

2. The twin-screw extruder for diaphragm production according to claim 1, characterized in that: The internal heating component (4) comprises a flow guide tube (402), one end of the flow guide tube (402) being connected to two flow shunt tubes (403), and one end of the two flow shunt tubes (403) away from the flow guide tube (402) being respectively connected to a heat flow inlet tube (404); Fluid channels (1021) are provided at the centres of the two rotating shafts (102) along the axial direction, and the two fluid channels (1021) are respectively connected to two heat flow inlet pipes (404).

3. The twin-screw extruder for diaphragm production according to claim 2, characterized in that: The internal heating component (4) further comprises a heat-conducting shell (401), the heat-conducting shell (401) being sleeved on one of the heating modules (301), the heat-conducting shell (401) being hollow inside and containing liquid, the top end of the heat-conducting shell (401) being connected to an end of the guide tube (402) away from the diversion tube (403), and being used for guiding steam generated after the liquid boils.

4. The twin-screw extruder for diaphragm production according to claim 2, characterized in that: A plurality of expansion channels (1022) are provided in the rotating shaft (102); the inner sides of the expansion channels (1022) are connected to the fluid channel (1021); the outer sides extend radially outward along the rotating shaft (102); and the expansion channels (1022) are located inside the kneading block (104).

5. The twin-screw extruder for diaphragm production according to claim 3, characterized in that: The preheating component (5) comprises a heating sleeve (501), the heating sleeve (501) being sleeved around the feeding cylinder (203), the heating sleeve (501) being hollow inside and connected to a pump body (502) via a pipeline, and the input end of the pump body (502) being connected to a connecting pipe (503).

6. The twin-screw extruder for diaphragm production according to claim 5, characterized in that: One end of the connecting tube (503) away from the heating sleeve (501) is connected to two collecting tubes (504), and one end of the two collecting tubes (504) away from the connecting tube (503) is respectively connected to heat outflow tubes (505), and the two heat outflow tubes (505) are respectively connected to one end of the two fluid channels (1021) away from the heat inlet tube (404).

7. The twin-screw extruder for diaphragm production according to claim 6, characterized in that: The interior of the heating sleeve (501) is connected to a first return pipe (506); one end of the first return pipe (506) away from the heating sleeve (501) is connected to the interior of the heat-conducting shell (401).

8. The twin-screw extruder for diaphragm production according to claim 3, characterized in that: The temperature sensing component (6) comprises a flow diversion shell (601), wherein an inlet pipe (603) and an outlet pipe (602) are respectively connected to the inside of the flow diversion shell (601), and a piston in the flow diversion shell (601) is connected to a sealing rod (605).

9. The twin-screw extruder for diaphragm production according to claim 8, characterized in that: The flow splitting shell (601) is connected to a second return pipe (606), and one end of the second return pipe (606) away from the flow splitting shell (601) is connected to the interior of the heat conducting shell (401).

10. The twin-screw extruder for diaphragm production according to claim 8, characterized in that: The temperature sensing component (6) further comprises a memory spring (604), one end of the memory spring (604) being fixedly connected to the inner wall of the diversion shell (601), and the other end of the memory spring (604) being fixedly connected to one end of a sealing rod (605).

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